1. Field of the Invention
The present invention relates generally to cable connectors, and more particularly to a cable connector for differential transmission (differential transmission cable connector).
2. Description of the Related Art
Data transmission systems include a normal transmission system and a differential transmission system. The normal transmission system employs an electric wire for each data item. The differential transmission system, using a pair of electric wires for each data item, simultaneously transmits a “+” signal to be transmitted and a “−” signal equal in magnitude and opposite in direction to the “+” signal. The differential transmission system, which has the advantage of being less susceptible to noise compared with the normal transmission system, is widely used in fields where signals are transmitted at high speed.
FIG. 1 is a schematic diagram illustrating a conventional differential transmission cable connector 1. FIG. 2 is a cross-sectional view of the differential transmission cable connector 1. FIG. 3 is an exploded view of an intermediary part of the differential transmission cable connector 1 illustrated in FIG. 2. In FIG. 1 through FIG. 3, X1-X2, Y1-Y2, and Z1-Z2 indicate the directions of width, length, and height, respectively, of the differential transmission cable connector 1.
As illustrated in FIG. 1 and FIG. 2, the differential transmission cable connector 1 includes a contact assembly 10, two intermediary interconnection boards (paddle cards) 20, and a differential transmission cable 60.
The intermediary interconnection boards 20 are attached to the back side (cable side) of the contact assembly 10. The differential transmission cable 60 has its end connected to the corresponding end of each of the intermediary interconnection boards 20. A shield housing 80 covers the contact assembly 10, the intermediary interconnection boards 20, and the end portion of the cable 60.
Referring to FIG. 3, first, second, and third contact connection pads 32, 34, and 36; first, second, and third wire connection pads 42, 44, and 46; and first, second, and third interconnects (interconnection lines) 52, 54, and 56 that connect the first, second, and third contact connection pads 32, 34, and 36 to the corresponding first, second, and third wire connection pads 42, 44, and 46 are formed on an upper surface 24 of each intermediary interconnection board 20.
The contact assembly 10 includes first signal contacts 12, second signal contacts 14, and ground contacts 16 soldered to the first, second, and third contact connection pads 32, 34, and 36, respectively. Further, first signal wires 72, second signal wires 74, and drain wires 76 at the end of the differential transmission cable 60 are soldered to the first, second, and third wire connection pads 42, 44, and 46, respectively.
Referring back to FIG. 1, each intermediary interconnection board 20 has a substantially rectangular shape. On the upper surface 24 of each intermediary interconnection board 20, the interconnects 52, 54, and 56 are formed with the same length, and the wire connection pads 42, 44, and 46 are aligned in a single row in the X1-X2 directions.
For related art, reference may be made to Japanese Laid-Open Patent Applications No. 2005-190691 and No. 2004-22413.